Introduction: Preimplantational genetic studies are used to achieve a better implantation rate and live birth, as well as to decrease the abortion rate; these techniques should be evaluated. Objective: To evaluate preimplantational embryo development in donor oocyte in vitro fertilization cycles with genetic studies. Design: Retrospective cohort study. Setting: Pranor Laboratory, 2008-2013. Material: In vitro fertilization with ovodonation (IVF-OD) cycles. Interventions.: 2 077 cycles of IVF-OD were evaluated, separated in 3 cohorts: Cohort 1, cycles with embryo biopsy on day 3, by means of an incision in the zona pellucida (ZP), for excision of a blastomer (n = 527); Cohort 2, cycles with a laser incision at day 4 of embryo development, for biopsy of the trophoblast in the blastocyst stage (n = 131) and; cohort 3, FIV-OD cycles without any intervention (n = 1 419). Main outcome measures...